Django: prefix/postfix language slug in i18n_urls - django

Question

I have a django-cms site, that uses i18n_patterns in urls.py. This works, urls are built like /lang/here-starts-the-normal/etc/.
Now, I would like to have urls like this: /prefix-lang/here-starts.... As there will be a couple of country specific domains, this wille be like /ch-de/here-... for Switzerland/.ch domain, /us-en/here-starts.... for the states, and some more. So, when the url would be /ch-de/..., the LANGUAGE would still be de. Hope this is clear?
As the content is filled with existing LANGUAGES=(('de', 'DE'), ('en', 'EN'), ...), I cannot change LANGUAGES for every domain - no content would be found in the cms, modeltranslation, only to mention those two.
How can I prefix the language slug in i18n_patterns? Is it possible at all?

Answer 1

I think a way without hacking Django too much would be to use URL rewrite facility provided by the webserver you run, for example, for mod_wsgi you can use mod_rewrite, similar facility exists also for uWSGI.
You may need to also post-process the output from Django to make sure that any links are also correctly re-written to follow the new schema. Not the cleanest approach but seems doable.

Answer 2

Working example, though the country/language order is reversed (en-ch instead of ch-en), to have it as django expects it when trying to find a language (ie, setting language to "en-ch", it will find "en", if available).
This solution involves a modified LocaleMiddleware, i18n_patterns, LocaleRegexResolver. It supports no country, or a 2 char country code, setup with settings.SITE_COUNTRY. It works by changing urls to a lang-country mode, but the found language code in middleware will still be language only, 2 chars, and work perfectly with existing LANGUAGES, that contain 2 chars language codes.
custom_i18n_patterns.py - this just uses our new resolver, see below
from django.conf import settings
from ceco.resolvers import CountryLocaleRegexURLResolver
def country_i18n_patterns(*urls, **kwargs):
"""
Adds the language code prefix to every URL pattern within this
function. This may only be used in the root URLconf, not in an included
URLconf.
"""
if not settings.USE_I18N:
return list(urls)
prefix_default_language = kwargs.pop('prefix_default_language', True)
assert not kwargs, 'Unexpected kwargs for i18n_patterns(): %s' % kwargs
return [CountryLocaleRegexURLResolver(list(urls), prefix_default_language=prefix_default_language)]
resolvers.py
import re
from django.conf import settings
from django.urls import LocaleRegexURLResolver
from modeltranslation.utils import get_language
class CountryLocaleRegexURLResolver(LocaleRegexURLResolver):
"""
A URL resolver that always matches the active language code as URL prefix.
extended, to support custom country postfixes as well.
"""
#property
def regex(self):
language_code = get_language() or settings.LANGUAGE_CODE
if language_code not in self._regex_dict:
if language_code == settings.LANGUAGE_CODE and not self.prefix_default_language:
regex_string = ''
else:
# start country changes
country_postfix = ''
if getattr(settings, 'SITE_COUNTRY', None):
country_postfix = '-{}'.format(settings.SITE_COUNTRY)
regex_string = '^%s%s/' % (language_code, country_postfix)
# end country changes
self._regex_dict[language_code] = re.compile(regex_string, re.UNICODE)
return self._regex_dict[language_code]
middleware.py - only very few lines changed, but had to replace the complete process_response.
from django.middleware.locale import LocaleMiddleware
from django.conf import settings
from django.conf.urls.i18n import is_language_prefix_patterns_used
from django.http import HttpResponseRedirect
from django.urls import get_script_prefix, is_valid_path
from django.utils import translation
from django.utils.cache import patch_vary_headers
class CountryLocaleMiddleware(LocaleMiddleware):
"""
This is a very simple middleware that parses a request
and decides what translation object to install in the current
thread context. This allows pages to be dynamically
translated to the language the user desires (if the language
is available, of course).
"""
response_redirect_class = HttpResponseRedirect
def process_response(self, request, response):
language = translation.get_language()
language_from_path = translation.get_language_from_path(request.path_info)
urlconf = getattr(request, 'urlconf', settings.ROOT_URLCONF)
i18n_patterns_used, prefixed_default_language = is_language_prefix_patterns_used(urlconf)
if (response.status_code == 404 and not language_from_path and
i18n_patterns_used and prefixed_default_language):
# Maybe the language code is missing in the URL? Try adding the
# language prefix and redirecting to that URL.
# start country changes
language_country = language
if getattr(settings, 'SITE_COUNTRY', None):
language_country = '{}-{}'.format(language, settings.SITE_COUNTRY)
language_path = '/%s%s' % (language_country, request.path_info)
# end country changes!
path_valid = is_valid_path(language_path, urlconf)
path_needs_slash = (
not path_valid and (
settings.APPEND_SLASH and not language_path.endswith('/') and
is_valid_path('%s/' % language_path, urlconf)
)
)
if path_valid or path_needs_slash:
script_prefix = get_script_prefix()
# Insert language after the script prefix and before the
# rest of the URL
language_url = request.get_full_path(force_append_slash=path_needs_slash).replace(
script_prefix,
'%s%s/' % (script_prefix, language_country),
1
)
return self.response_redirect_class(language_url)
if not (i18n_patterns_used and language_from_path):
patch_vary_headers(response, ('Accept-Language',))
if 'Content-Language' not in response:
response['Content-Language'] = language
return response